Switch construction



L. P. HUTT.

Sv'TCH CONSTRUCTION.

AvPLlcAnoN man DEc.1o,1917.

1,342,999, Patented June 8,1920.

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UNITED STATES PATENT OFFICE.

LEONARD P. HUTT, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK` SWITCH CONSTRUCTION.

Specication of Letters Patent.

Patented June 8, 1920.

Application, filed December 10, 1917. Serial Noi 206,361.

To all whom t may concern:

Be it known that I, LEONARD I. I-IUTT, a subject of the King of Great Britain, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Switch Construction, of which the following is a specification.-

rIhis invention relates to switch construction and has for its Object an improved construction and arrangement of parts whereby the li'fe of the switch contacts is materially increased.

More specifically this 'invention relates to electro-magnetically actuated switches or contactors designed for heavy duty such as where it is necessary to make and break large currents in rapid succession.

It has been proposed to accelerate the opening movement of contactors beyond that naturally aiforded by gravity by applying additional force to the opening movement such as that obtained from a spring compressed by the closing movement, in order to dissipate the arc more quickly and consequently increase the life of the contactor. It was found desirable to have such additional acceleration applied not only during that-portion of the opening movement in which the contact making members are in rolling contact or wiping on one another but also for an appreciable interval of time after the contacts have separated in order to secure the largest practical' increase in the life of the contactor.

In accomplishing is increase in the life of contactors in accordance with the practice of the prior art to get the desired acceleration, it was necessary to increase the size of the spring and consequently to increase the Size of the actuating electromagnetic winding, which increase was objectionable because it necessitated anincrease v in both the weight and size of the contactor and required more energy to operate it. The increase in weight was particularly objectionable because the added inertia of the moving parts created a tendency for the contact making members to stick or freeze to each other.

In carrying my invention into effect, I

v employ a double pole contactor ordinarily designed to break a circuit in two points simultaneously and so arrangev one set of contact making members with respect to the For a more complete understanding of the nature and objects of this invention reference should be had to the following detailed description, taken in connection with the accompanying drawing in which Figure l is'a side elevation of an electromagneti- `cally actuated contactor embodying my invention, while Fig. 2 is a front elevation of such contactor and Fig. 3 is a view indicating in diagrammatic fashion the arrangement of the contacts ina power circuit.

Referring now to the drawing, 5 denotes a back of insulating material on which is mounted a magnetic frame 6 carrying an electromagnetic winding 7 arranged when energized to actuate theI armature 8, which has a bifurcated portion 9 pivoted at 10 astride a projecting portion of the magnetic frame 6. e

The armature 8 `is shown as having rigidly secured to it, two horizontally disposed insulating rods or tubes 11 and 11 which serve as the supporting means for the mov able members 12 and 12 of the two sets of contacts. These movable members are mounted on the brackets 13 and 13 pivoted in the bifurcated'uprights 14 and 14 which are secured on the rods or tubes 11 and 11.

v The stationary. members 15 and 15 of the two sets' of contacts are mounted on the brackets 16 and 16 which are, in turn mounted on the back 5.

The members 15 and 15 are lin conducting relation with the upper set of termina-ls 17 projecting rearwardly from the back 5, while the movable members 12 and 12 are arranged to be in conducting relation with The motion of the brackets 13 and 13 is limited by means of the heels 21 and 21 which abut against portions of the uprights. The springs 20 and 20 are compressed by the closing movement of the contacts and consequently apply an acceleration in addition to gravity to the opening movement.

In order that part of this additional acceleration may be applied for anappreciable vanced the closing point of the other set by inserting a liner or spacer 22 between the back 5 and its supporting bracket,here shown as bracket 16. By this arrangement the two sets of contacts do not open simultaneously, but' members 12 and 15 open first thereby allowing the resilient effect between the ,of the coil 23.

The operation of this invention is as f ollows:v v

When it is desired to close the contactor the winding 7 is energized from the control circuit in the usual manner. The winding 7 accordingly attracts the armature 8 moving the members 12 and 12 to closed position. y The member 12 first engages the member 15 by reason of its advanced position afforded by the spacer 22 and then members 12 and l5 engage.

The spring 20 is consequently more highly compressed than spring 20 and applies an acceleration to the opening movement,'when winding 7 is denergized, after contact members 12 and 15 are separated until members 12 and 15 separate. l

In practice the advancement of the closing point of one member by one eighth of an inchv has served to increase the life of a contactor approximately 75 per cent. y

As will be observed from Fig. 3, a multiple break in the electric circuit controlled by the switch is effected g that is, the circuit in Fig. 3 is opened at two points. Although the switch does, not-open the twol breaks in the circuit simultaneously, the opening of the one break occurs .a very short interval of time after the opening Vof the first break.

While I have here shown an embodiment of my invention which is at present the best means known to me for carrying the same into effect, I would have it understood that ing contacts arranged to effect a multiple by Letters Patent of the United States. is interval of time. after'one set of these contact making members has opened I have ad 1. An electromagnetic switch comprising a plurality of pairs of simultaneously ac.- tuated relatively movable resiliently engaging contacts arranged to effect1 a multiple break in a circuit, vthe distance between one pair of contactslin the open position being less than that between the remainder of the pairs of contacts, whereby the opening movement of said remainder of the pairs of contacts after their separation isiaccelerated responsively to the resilient effect between said one pair of contacts.

2. An electromagnetic switch comprising a plurality of pairs of simultaneously actuated relativelylmovable resiliently engagbreak in a circuit, the distance separating one pair Aof contacts in the open position being less than the distance separating the remainder of the contacts, and means whereby the opening movement of saidvremainder of' the pairs of contacts after their separation is accelerated responsively to the resilient effect between said one pair of contacts.

3. An electromagnetic switch comprising a plurality of pairs of simultaneously actuated relatively movable resilently engaging contacts arranged to effect a multiple break in a circuit, the distance separating one pair of contacts in the open position being less than the distance separating the remainder rof the pairs of contacts, and means for advancing the'. closing point of said one pair of contacts whereby the opening movement of said remainderof the pairs of contacts after their separation is accelerated responsively to the resilient effect between said one pair of contacts.

4. An electromagnetic switch comprising a plurality of' pairs of fixed and movable resiliently. engaging contacts arranged to 115 effect a multiple break in a circuit', means for simultaneously moving the movable contacts, a back, brackets thereon for supportwith an electromagneticlwinding, of a pair of stationary contact members, a pair of movable contact members arranged to be Simultaneously actuated by said winding to close a multiple break in a circuit, means for holding said members in resilient engagement when said movable members are in switch closed position; the distance between one pair of engaging members in the open position being less than that between thev other pair, so that said resilient means still applies acceleration to the opening movement of the movable contacts after the other pair has opened.

6. In an electric switch, the combination with an electromagnetic winding, of a pair of stationary contact members, a pair of movable contact members arranged to be siniultaneously actuated by said winding to close a multiple break in a circuit, means adapted to hold said members in resilient engagement when said movable members are in switch closed position; one pair of engaging members having their closing point advanced so that the distance between this pair in the open position is less than that between the other pair, whereby said resilient means still applies acceleration to the openingk movement of the movable contacts after the other pair has opened.

7. In an electric switch, the combination with an electromagnetic winding, of apair of stationary contact members, a back, a pair of brackets supporting said stationary members from said back, a pair of movable contact members arranged to be simultaneously actuated by said winding to close a multiple break in a circuit, a spring adapted to hold each of said movable members in resilient engagement with said stationary members when in switch closed position, one of said stationary contacts being advanced with reference to the other so that the spring associated with said one of said contacts still applies acceleration to the opening movement of said other pair of members after said other pair of members has opened.

8. In an electric switch, the combination with an electromagnetic winding, of a pair of movable contacts arranged to be simultaneously actuated by said winding, a pair of stationary contacts coperating therewith, a back, a pair of brackets for supporting 'said stationary contacts at equal distances .from the movable members, a spring adapted to hold each of said movable members in resilient engagement with said stationary contacts when the switch is in closed position; and a spacer located between the back and one of said contacts whereby the point at which the said contact is engaged by its movable contact is advanced, thereby enabling the spring, reacting against the movable contact in engagement therewith to apply acceleration to the opening movement of the movable contacts after the other pair of contact members has opened.

9. In an electric switch, the combination with an electromagnetic winding, of a pair of stationary contact \members, a back, a pair ,of brackets supporting said stationary members from said back, an armature actuated by said winding, a pair of pivoted brackets arranged to be supported and moved simultaneously by said armature to effect a multiple break in a circuit, a spring arranged to react against each' pivoted bracket and its armature support, contact members carried by each pivoted bracket and arranged to be held in resilient engagement with said stationary members when in switch closed position; one of said first named brackets being so mounted that the closing point of its pair of engaging members is advanced enabling its reacting spring to apply-acceleration to the o ening movement of said armature after t e other pair has opened. V

In witness whereof, I have hereunto set my hand this 7th day of Dec., 1917.

LEONARD P. HUTT. 

